Patients with subcutaneous or lymph node metastases have been treated with alpha interferon (IFL-rA) at doses of 3, 9, 18, 36 and 50 x 106 units per lesion to determine local toxicity, efficacy and cellular response to a pure lymphokine prepared by recombinant DNA technology. Eighteen patients have been entered and 15 were evaluable, receiving at least 3 doses. Local erythema in the skin over a responding lesion has been the only local toxicity. One patient with a prior history of seizures had a grand mal seizure with the first dose. One patient receiving 3 million units per lesion had a partial response. No other responses were seen until a dose of 36 million units/lesion was administered: there has been one complete response and three partial responses in patients receiving this high dose level. No cellular infiltrate has been identified which can be attributed to the administration of interferon.